Plastic floor board



FIG. 1 is a perspective view of a plastic floor board;

FIG. 2 is a rear plan view thereof;

FIG. 3 is a left side view thereof (the right side view being a mirror image of the left side); and,

FIG. 4 is a top view thereof.

The lines shown in phantom are for illustrative purposes only and do not form part of the invention. 

The ornamental design for a plastic floor board, as shown and described. 